STRESS DISTRIBUTION MODEL IN WATER INJECTION WELL

Geomechanics study is often overlooked in oil and gas industry whether during drilling, completion or production phase in Malaysia. Generally, geomechanics is the study of behavior of soil and rocks. These two principles are connected each other and can be further explained in stress and strain distribution concept. This project covers the study of rock mechanics by manipulating the vital parameters such as Poisson’s ratio and Young’s Modulus, effects of stress distribution around water injector well. The study is conduct by two approaches; one-dimensional approach which cover the changes around the wellbore and three-dimensional approach, which cover the reservoir simulation. In one- dimensional approach, the parameters studied are Young’s modulus and Poisson’s ratio while in three-dimensional approach, the parameter of interests are well injector pressure, plastic shear strain and plastic displacement. The results from the simulations is as the water is injected, the stress decrease and stain increased. On the other hand, in reservoir approach, after water is injected, the well injector pressure decreased, plastic shear strain increased and plastic displacement decreased. A positive stress means compaction of rock which results in negative strain while a negative stress means expansion of rock and results in positive strain. The water injector pressure is decreased after water is injected is due to the pressure decline is much greater as compared to the one with injection. An increased in plastic shear strain means pore spaces expand or increase because of the more pressure applied after water injection. The negative value in z-plastic displacement means compaction drive took placed after water injection which is good for the reservoir.